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