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