One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,12,29,50,77,70,8,13,32,51,38,56,89,111,9,15,33,53,36,90,88,124,6,34,30,86,7,14,31,52)(3,10,17,40,62,98,116,113,18,43,63,101,68,105,120,123,20,44,65,102,91,103,126,128,35,41,87,99,19,42,64,100)(4,21,24,55,37,92,85,47,27,72,79,107,76,109,83,46,23,71,75,112,81,110,84,54,25,80,78,48,26,49,28,11)(16,57,59,104,67,122,82,96,22,73,74,125,93,127,117,94,58,114,115,106,121,108,119,45,66,69,118,95,60,97,61,39)(1,3)(2,10)(4,22)(5,17)(6,35)(7,19)(8,18)(9,20)(11,45)(12,40)(13,43)(14,42)(15,44)(16,25)(21,69)(23,66)(24,74)(26,67)(27,58)(28,82)(29,62)(30,87)(31,64)(32,63)(33,65)(34,41)(36,91)(37,93)(38,68)(39,47)(46,96)(48,106)(49,108)(50,98)(51,101)(52,100)(53,102)(54,94)(55,95)(56,105)(57,72)(59,78)(60,81)(61,84)(70,113)(71,73)(75,118)(76,121)(77,116)(79,115)(80,114)(83,119)(85,117)(86,99)(88,126)(89,120)(90,103)(92,97)(104,107)(109,122)(110,127)(111,123)(112,125)(124,128) involution — undirected(1,4,8,25,9,23,6,27)(2,11,13,54,15,46,34,47)(3,16,18,66,20,58,35,22)(5,28,32,84,33,83,30,85)(7,37,29,26,38,81,36,76)(10,39,43,45,44,94,41,96)(12,49,51,110,53,109,86,92)(14,55,50,48,56,112,90,107)(17,61,63,119,65,117,87,82)(19,67,62,60,68,121,91,93)(21,70,80,111,71,124,72,52)(24,77,78,89,75,88,79,31)(40,97,101,108,102,127,99,122)(42,104,98,95,105,106,103,125)(57,113,69,123,114,128,73,100)(59,116,118,120,115,126,74,64)A 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.