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