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