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