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