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