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