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