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