Hum, im just brainstorming here, but something like:

-----------------------------------------------------|
-----------------------------------------------------|
7---777-777-777-5-1--111-111-111-5-7-----------------|
7---777-777-777-5-3--333-333-333-5-7-----------------|
5---555-555-555-3-3--333-333-333-3-5-----------------|
-----------------------------------------------------|

I think this is the main riff, but this is just to get others in the mood to tab this 
correctley!