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