It is integrated into the home button. Only the guide graphics are on the display. They can help guide you during enrollment, but if you want to use the fingerprint sensor one handed then you have to enroll the fingerprint the way you intend to use it... And it needs to be a fairly vertical swipe. I was able to use it with my thumb swiping vertically, but oriented mostly sideways, even though I have my forefinger enrolled pointing up with a downward motion as usually shown.
Sadly the demos and instructions are much less useful than a video of typical use and "enroll the way you want to use it". Typical error rate for my thumb is 10% so I didn't error out during any of my testing. However, I have large fingerprint ridges so people with smaller hands might have more issues... TouchID works great for me and bad for my ex.