This my first tab, så I'll just try :)
Riff 1 (The C7)
G|----5-3-----------5-3----------------|
D|--------5-3--1--------5-3------------|
A|--3-------------3--------------------|
E|-------------------------------------|
Riff 2 (The F7)
G|-------------------------------------|
D|----3-1----------3-1-----------------|
A|--------3-1----------3-1-------------|
E|--1----------4-1---------------------|
There's something more, but i couldn't find out, so you must be content with this :)