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