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