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