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