Graves potential lies in his ability to do a lot of burst damage. The following is what I present to The Summoners as a Graves build of destruction.

Pure damage runes to start with armor pen to allow for enough damage early game when hitting with your Q. Teleport and Ignite for two different reasons. Teleport on Graves will allow him to show up and wreak havoc anywhere, being it another player or just a minion wave. Graves is an excellent farmer. Ignite is for early game kills once you combo your buttons together to do major burst damage on an enemy to ensure the kill. I run a 21/0/9 masteries page as shown.

Items within a certain order are crucial for Graves to survive. Start with "Boots and 3 health pots". Try and not return to your base until level 6, ensuring you have enough money to by "Beserkers Greaves" and "2 more health pots". This should be achieved by putting out plenty of harass by dashing the enemy with "E" and following with "Q". If you feel you can surly get the kill with Graves, follow the combo as "E; W; Q; R;". This will ensure that you hit with all your damaging moves as well as land a good chunk of basic attacks, "Ignite" also if you must. As the game continues on, work on the "Trinity Force" next piecing it together in this order, "Phage; Zeal; Sheen". This will give you early health and slow to chase down, followed you well needed attack speed. Usually you'll have enough money to skip over the "Sheen" and outright buy the "Trinity Force". Once you get your lanes tower down, unless already done, work on getting the "Bilgewater Cutless" as it will provide you with the lifesteal needed to last in a fight now. Follow through into a "Hextech revolver" and finally into a "Hextech Gunblade". The "Tiamat" may seem like a waste, but for only a little over 2k gold, it gives a well worth it, 50 AD, mana regen, and health regen. This item is mainly used to farm up lanes even faster seeing that Graves should be able to have the most minion kills usually. This item is subject to chance based on preference to the player and conditions. The "Infinity Edge" will ramp up your damage output overall, and increasing your critical chance and dealing damage of roughly 600 or more. The final item, "Phantom Dancer" is to increase Graves attack speed, as he will feel like he needed it by now. It also raises your critical chance farther to allow more constant heavy hits, topped with the "Trinity Force" proc.