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