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