Main Riff:

G|------------------------------
D|------------------------------
A|--------------------2-2-22-2-3
E|--2-2-22--23-3-33--3----------

In the beginning there's a variation that goes like this:

G|----------------------------
D|----------------------------
A|---------------------2-----0
E|--2-2-22--23-3-33--3--------


"I wanna be pretty..."

G|-----------------
D|-----------------
A|--------------2-2
E|--2-2---3-3------


"Get down, get down..."

G|---------------------------
D|---------------2-2---------
A|--4---4---0-0-------2-2-2-2
E|---------------------------

If you want to play along with the whole guitar part and not just what the 
bass plays, here are all the notes:

G|-------------------------------------------
D|-------------------------------2-2---------
A|--4-4--4------4-4--4------0-0-------2-2-2-2
E|---------2-4---------2-4-------------------