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