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