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