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