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