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