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