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