The volume button sits on the right side of the phone right near the power button and exists as a rocker rather than two separate buttons. (slashgear.com)
This image, however, fits with a recent leak we've seen, so it's possible we know the design of the front side of this phone as well. (androidheadlines.com)
The power button on the right hand side of the phone is easy to reach with your thumb, while the volume rocker sits just above it and again is easy to tap. (techradar.com)