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