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