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