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