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