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