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