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