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