He's performed it with with capos on 2 and 3. I think he uses it on 2 the most though.

Riff 1:

e||----------------|----------------|----------------|----------------||
B||--3-----3-------|--2-----2-------|--0-----0-------|--0-----0-------||
G||----4-----4---4-|----2-----2---0-|----1-----1-1h2-|----1-----1---0-||
D||------4-----4---|------2-----2---|------2-----2---|-------2----2---||
A||2---------------|0---------------|----------------|----------------||
E||----------------|----------------|0---------------|0---------------||

Riff 2 (only appears after the chorus in some versions):
e||--2-------------|--------------|----------------|----------------||
B||----3---5-2-----|--2-------2---|0-----0---------|0-----0---------||
G||--------------4-|----2---2---2-|--1-----1---1h2-|--1-----1---0---||
D||----------------|------2-------|----2-----2-2---|----2-----2-----||
A||2-----2-----2---|0-------------|----------------|--------------0-||
E||----------------|--------------|0---------------|0---------------||