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