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