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