Standard tuning.
Chords go from Gmaj to Cmaj, to Dmaj, and back to Cmaj.

e|-----------------------------------------|
B|------0---------1-----------3--------1---|
G|----0---0---------0-------2---2--------0-|
D|-----------------------0-----------------|
A|------------3---------------------3------|
E|-3---------------------------------------|
e|-----------------------------------------|
B|------0---------1-----------3--------1---|
G|----0---0---------0-------2---2--------0-|
D|-----------------------0-----------------|
A|------------3---------------------3------|
E|-3---------------------------------------|
e|-----------------------------------------|
B|------0---------1-----------3--------1---|
G|----0---0---------0-------2---2--------0-|
D|-----------------------0-----------------|
A|------------3---------------------3------|
E|-3---------------------------------------|
Play this one riff over and over.