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