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