Sorcery + Precision as Graves Runes
This setup uses Phase Rush on Graves as the keystone rune. Phase Rush, upon landing three separate attacks or abilities with Graves onto an enemy champion, grants a burst of movement speed to you. This is a great way of weaving in and out of danger during full scale fights, as well as giving your opponent less of an opportunity to trade damage back onto you in smaller skirmishes.
Pros continue down the Sorcery tree, picking up Nimbus Cloak, which grants movement speed upon casting a Summoner Spell. This works amazingly well with junglers in particular as they take the shortest cooldown Summoner Spell, Smite. Absolute Focus allows Graves to clear camps faster, since no damage should be taken if you know how to clear the camps properly. Waterwalking grants movement speed in the river, which helps Graves get around the map quicker. The extra damage will also help your team in all important dragon and baron fights.
As secondary Pros prefer the Precision tree, taking Triumph and Legend: Alacrity. These runes are great at helping Graves scale a bit better and allowing to gain some health after taking down an enemy champion.