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