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