Hi, i'm actually a gold III player on EUW and played a few games with Evelynn on s4.
The S5 jungle changes really hurt her early clears, and without a strong leash, she may have problems to reach level 3.
Rito was aware of the problems and buffed her slightly :

Passive - Shadow Walk
+2% missing mana per second

E - Ravage
Strikes now apply on-hit effects

The most interesting change is about ravage, which helps alot for the early clear, i'll explain this later.

I take classic AD jungle runes, you will need AS quints and AD marks, armors seals are necessary because you are really squishy without, and the scaling MR are a better choice than flat because you will take magic damage a bit later in the game.

You can also choose scaling CDR blues if you want your ult's CD reduced.

Now i'll explain why i take Ravage level 1.
If you start with golems and smite them, Ravage will proc an additionnal golem stack.
Moreover, Ravage resets your auto attack.
So, if you try AA > E > AA, it will bring 3 stacks of golem debuff in a short window of time.
The stun make the early clear a bit safer, but still risky, Evelynn is still a squishy **** at early levels.

By maxing Ravage, you'll be able to get a strong AS buff, which combined with the Devourer enchantmant, make your jungler clears and ganks really strong.

This is my first guide right here. I'll add some code a bit later and answer questions. Thanks for reading, and don't forget to try it before rating.