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