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