Yes, you can find the rest room. If you want to visit the city, you are allowed without a visa. Indian passport holders can stay in HK without a Hk visa for 14 days. There are Airport Express and Airport Bus connecting the downtown and the airport. I think you may return to the airport around three hours prior to the departure time. Nor far from the airport, you can go to the Disneyland and the Po Lin Monastery. The Po Lin Monastery boasts the world-biggest Buddha statue. It's really very attractive.