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