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