The basic riff is:

E ----------------------------------------
B ----------------------------------------
G ----------------------------------------
D ----------------------------------------
A -------------------------------------5--
E --3---1---0---1--3---3-5-3-5-3-5-3-5----


There is also a part in the song where the riff changes, it goes unto a
different string like this:

E ----------------------------------------
B ----------------------------------------
G ----------------------------------------
D -------------------------------------5--
A --3---1---0---1--3---3-5-3-5-3-5-3-5----
E ----------------------------------------