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