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