This is played with 8-string guitars on ?step down tuning.
I didn't find this tab anywhere. I watched Meshuggah's own lesson for this riff and it 
like this.
Everybody don't have 8-string guitar, but this is right tab for 8-string guitar.

Rhythm is ooo-o-ooo-o-ooo-o-ooo-o-...... etc
5/ means you have to bend fifth fret.

Eb-----------------|
Hb-----------------|
Gb-----------------|
Db-----------------|
Ab-----------------|
Eb-0------0-----0--|
Bb----5/-----5/----|
F------------------|

I don't have time to tab whole rhythm and bending. hope you understand that way.

Then the lower part of the riff goes like this for real

Eb-------------------------------------|
Hb-------------------------------------|
Gb-------------------------------------|
Db-------------------------------------|
Ab-------------------------------------|
Eb---------------------1--10--4--------|
Hb-------------------------------3--0--|....
F--1-------------2--5------------------|

so, strum that certain fret for the certain rhythm.
Hope you get it :)