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