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