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