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