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