I am in a similar position, I work mainly with Christians, but there is a few Muslims. I think religion is quite different in the UK to the US, but at work I do have a large amount of colleagues from overseas.
I am an atheist and lean towards humanism. i had a situation a couple of weeks back with my ward manager. We were discussing Easter rota and I was only person working friday, saturday, sunday and monday. She asked if I was upset because I couldn't go to church. I told her that I didn't go to church because I wasn't a Christian. She then started quizzing me about how I believed we got here, what did I do when things were bad, did I really never pray etc. All questions I didn't really answer because I didn't feel the need to justify my beliefs/lack of. I told her I didn't think it was appropriate to discuss religion at work and got out of there quickly.
I'm fairly open about myself at work and generally, open about my religion (lack of), sexuality, history of mental health problems. I think that some people try to take advantage of my openness and ask inappropriate questions. an example, I am happy to tell you that the scars on my arms are from self harm (it is fairly obvious), but it's not appropriate for you to ask me what happened in my childhood to cause me the problems I have had.
I hope you find someway to be comfortable at work