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