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