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