Riff 1:  The 4's are played 8 times in the intro only and are played 4 times in the rest of the song 
G----------------------------------------------------------------------------------
D-----------------------------------------------------------------------------------
A---------------5-5--------------------------5-5---7-7---------------------5-5-----------7-7-7-7---4-4-4-4-4-4-4-4---
E-2-2-2-2---------5-5--------2-2-2-2-----------------------2-2-2-2----------5-5-----

Riff 2:
G-----------------------------------------------------------------------------------
D-----------------------------------------------------------------------------------
A--------------------------7-7-7-7----------------------------------------7-7-7-7-4-4-4-4--
E---2-2-2-2---5-5-5-5-------------7-7-7-7------2-2-2-2-5-5-5-5----------------------

Riff 3:
G-----------------------------------------------------------------------------------
D-4-4-4-4-------------------------------------4-4-4-4-------------------------------
A-------------------------7-7-7-7------------------------------------7-7-7-7-4-4-4-4
E--------------5-5-5-5--------------7-7-7-7--------------5-5-5-5--------------------

Riff 4:
G-----------------------------------------------------------------------------------
D-----------------------------------------------------------------------------------
A--------------------------7-7-7-7-4-4-4h5p4----------------------------------------
E-2-2-2-2-5-5-5-5-------------------------------------------------------------------

Order:
Riff 1: 3x
Riff 2: 1x
Riff 3: 1x
Riff 1: 1x
Riff 2: 1x
Riff 3: 1x
Riff 4: 6x
Riff 2: 2x 
Riff 3: 2x