I grew up in Memphis, and I absolutely love my city.. most parts of it. The Graceland area is not safe. If you're going to visit, make sure you visit during daylight. And definitely don't stay at a hotel/ motel in that area.
The area around Graceland is NOT the greatest. Daytime is fine. But at night I would take a cab and I'd be sure to lock up away any valuables.
In fact, you might want to stay in another area and just drive out to Elvis' place.