One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6,9,14,28,41,57,54,11,16,30,43,10,15,29,42)(7,12,18,33,19,34,50,64,21,36,52,66,20,35,51,65)(8,22,24,44,31,60,59,39,26,55,58,38,25,40,27,13)(17,45,46,37,23,53,56,62,48,67,68,61,47,63,49,32)(1,2,4,3)(5,7)(6,12)(8,23)(9,18)(10,20)(11,21)(13,37)(14,33)(15,35)(16,36)(17,25)(19,28)(22,53)(24,56)(26,47)(27,46)(29,51)(30,52)(31,48)(32,38)(34,41)(39,61)(40,45)(42,65)(43,66)(44,62)(49,58)(50,57)(54,64)(55,63)(59,68)(60,67)(5,8,11,26)(6,13,16,39)(7,17,21,48)(9,27,30,59)(10,31,28,25)(12,32,36,62)(14,40,43,60)(15,44,41,38)(18,49,52,56)(19,47,20,23)(22,54,55,42)(24,57,58,29)(33,63,66,53)(34,61,35,37)(45,64,67,65)(46,50,68,51)(1,3,4,2)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.