One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,10,4,11,16,35,5,12,17,36,20,39,49,75,6,13,18,37,21,40,50,76,24,42,52,78,55,81,91,110,7,14,19,38,22,41,51,77,25,43,53,79,56,82,92,111,27,44,54,80,58,83,93,112,61,84,94,113,95,114,119,126,8,9,15,30,23,31,45,65,26,32,46,66,57,69,85,100,28,33,47,67,59,70,86,101,62,72,88,103,96,106,115,121,29,34,48,68,60,71,87,102,63,73,89,104,97,107,116,122,64,74,90,105,98,108,117,123,99,109,118,124,120,125,127,128)(2,9)(3,15)(11,31)(12,32)(13,33)(14,34)(16,45)(17,46)(18,47)(19,48)(39,69)(40,70)(41,71)(42,72)(43,73)(44,74)(49,85)(50,86)(51,87)(52,88)(53,89)(54,90)(81,106)(82,107)(83,108)(84,109)(91,115)(92,116)(93,117)(94,118)(114,125)(119,127) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.