One vertex per element, one color per generator, with an edge from x to x·s.
(2,6)(3,4)(7,8)(9,10,13,18,14,17,25,31)(11,19,22,32,21,15,26,28)(12,16,24,30,23,29,36,39)(20,33,34,40,35,27,37,38)(1,2)(3,6)(4,8)(5,7)(9,11,14,21)(10,15,17,19)(12,20,23,35)(13,22,25,26)(16,27,29,33)(18,32,31,28)(24,34,36,37)(30,40,39,38)(1,3,5,4)(2,6,7,8)(9,12)(10,16)(11,20)(13,24)(14,23)(15,27)(17,29)(18,30)(19,33)(21,35)(22,34)(25,36)(26,37)(28,38)(31,39)(32,40)(11,21)(12,23)(15,19)(16,29)(22,26)(24,36)(28,32)(30,39) involution — undirectedA 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.