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