I'm curious to know why I don't see most Indian batsmen playing sweep shot against spin which is a regulation shot overseas.
Because all Indian pitches are suitable for the spin and all Indian Batsmen played lot's of spin from childhood, That is why all Indian batsmen know how to play spin without any risk and they also know which shot is safer then sweep. And overseas player is not good against spin so they always preferring sweep against spin.
The article Philip refers to also kinda answers the question. They rarely need to play the sweep in India, and most in the current squad are uncomfortable with it. Pujara prefers to come down even for a single, Rahane prefers to stay back. Kohli does sweep at times, but he doesn't need to.
While they did try to learn to sweep Moeen away according to the article, it makes sense to stick to your tried and tested methods. It's a different matter they didn't work very well.