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