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