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