They've probably thought about your position much more than you have thought about theirs, so you can briefly explain your position and ask what they think is important for you to know or think about.

I would probably open with "Why are there so many theologians of false religions? Why do so many smart people get it so wrong, and how do we avoid making those same mistakes?" If the subject of my religion came up, I'd admit that I'm an atheist, but that I worry about falling for the same traps that Muslim or Hindu scholars do. After that it would depend on where the conversation went, but I'd like to find out their thoughts on a system where 4/5ths of the planet is sent to eternal torture because they made a mistake about which book to believe.