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