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