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