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