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