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