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