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