Ezreal - His high range, high poke, and high mobility can be incredibly difficult for Graves to handle.
Miss Fortune - Higher Attack Speed, range, and harassment to zone out Graves in lane and can lock him down for team fights.
Caitlyn - Her high attack range, ability to outfarm almost any carry, and her heavy harassment makes her difficult to deal with.
Sona - Can zone Graves out and can be a nusence. As long as her carry can keep her alive incase Graves goes on the offensive, she should be perfect.
Lux - High zoning abilities and quick burst can lock Graves down for her carry at ease.
Leona - Her range on Zenith Blade is roughly the AA range on Graves, meaning if Graves wants to attack her, she can attack back. Plus her high CC can lock Graves down longer than the carry should need to take him out.