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