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