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