Roopa - Feeling a need to please your supervisor is pretty natural I think, particularly if they are charismatic. My supervisor was one of the best in his field, and it's a field which I love, so I was eager to please, too!
Don't worry though - as long as you work reasonably hard you'll do fine. Nobody expects you to work 120 hours a week. All they expect you to do is take your work seriously. Even if you don't get a distinction, but in your research project you come up with some good ideas, then I think you'll be fine. And if you've got three supervisors, you've got a good chance of pleasing at least one of them!