I found this from just picking around, it's pretty simple. This is just a bass version
of the main riff, not the bass track to the song (because I don't think there is one
other than the kickdrum beat in the background).

G|----3--6--3------------------------------------------||
D|-4--------------3--6--3-------------------3--6--3---*||
A|-------------4---------------3--6--3---4------------*||
E|--------------------------4--------------------------||