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