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