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