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