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