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