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