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