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