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