Well I have a clear and rather poetic view of the subject.
A Women who is not only modest in appearance but also most modest in her outward and inward manners is truly beautifull I knew many such Women who outwardly might not have been the prettiest sight on Earth, some were blind others disfigured by the wicked world but they were as beautifull as any of Allah's creations. Why?
Well is it not simple? Surely Beauty is not limited to looks but actions and even thoughts as well. One blind Woman was a school tutor she wanted to be a famous designer but she lost her sight and so she dedicated her life to teaching children instead she is now happily married to a friend of mine who truly loves her and to see them both you could not tell that she was blind for her eyes still seem normal only at a close inspection would one notice the pupils were a little too large.
As for Sexy that is merely an outward and inward behaviour trait. A Woman can be beautifull but not sexy... Why? For she does not flaunt her beauty to make gains, she does not use her beauty for evil purposes and she does not act in a dishonourable manner. To be sexy a Woman stops being so much as human and instead takes on an animalistic grace, she loses any sense of honour and respect. Such Women in my view are not at all dignified and thier manners are disgracefull. She no longer has beauty, she may look appealing but inside she is more animal than Woman... such a Woman could be a plaything... or a creature of evil... a temptress or a cold hearted demon but she could never be a gentle Mother and while they can play with mens minds they seldom control mens hearts.
I brace myself for the bombardment from Femminists and thier supporters and such Men who prefer Sexy over Beautifull but seriously think deeply and you will know I speak truly and from the pure wisdom of soldiers and sages throughout the ages. :)
I'd find both compliments but also depends on the context and who's saying it eg. to me a guy calling u sexy even if you're dressed down with little/no makeup is nice whilst if an auntie says it lol that's more likely a criticism..
Also, you don't necessarily have to 'flaunt' it to be sexy.. I think a girl can also have a sexy look/sensuous face (a good example would be Cristiano Ronaldo's new gf Irina Sheik or Megan Fox or Angelina Jolie.. however modestly she dresses a lot of men would obviously look at her and find her sexy)
Thankyou Faris Sahab and other members for your input :flower1:
In my personal opinion, I think, evil connotation attached with sexy look is not always applicable.
There is margin of natural attraction which has some effects on humans and other creatures.
Was sexy looks not present 500 years ago, or 150 years ago during Mirza Ghalib’s time period. Yes it was !
I have forensic evidence to prove this fact
I agree with Deeba1234 :k:
just to quote a poet of our time. Famous Indian Poet Mr. Javaid Akhtar once said that sexy look is not dependent on revealing cloths or nasty dancing. It can be explored in simplicity with grace and style.
He told that he told audience that he find this actress most sexiest in this song.
words can’t bring them dowwwwwwwwwwwn, oh noooooo 
And I think we look our best in desi clothes.