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