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