In case you wish to Visit Shriwardhan, Mangaon station is the ideal place to get off as plenty of buses, as both the Janta Gadi (Passenger train equivalent of MSRTC) and Semi Luxury buses on Mumbai-Shriwardhan-Bagmandla route are availiable here.
PS: do take a tablet for motion sickness here. The road has more twists and turns than an 8 year long soap opera and is sure to make you feel "funny" in your tummy.