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