This is the way I personally play Diana. I have zero problems with jungle sustain and the ganks work very well. I am not very high elo (1300) but I have had no problems with this build. The sheen/madreds combo early keeps your ganks threatening while helping your early dragon and jungle capabilities. This guide will be fairly brief in description as Diana is a fairly easy champion to play, but I will add more if this guide becomes popular.

When jungling I often get ask for a decent leash on blue so I don't have to worry about being counterjungled as I only open with one potion. I go the standard route of Blue -> Wolves -> Wraiths -> Golems -> Red Buff. You should use your potion near the end of golems or before you start red. Avoid using your shield a second time during golems and be careful not to use all your mana in the jungle (when you don't have blue).

For my runeset I have a very earlygame oriented build. This helps me jungle and do decent damage before I start to buy any real damage items (RoA). My masteries are based around keeping a good clear time and decent damage as well, helping with early sustain (Longsword 1pot opener).