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