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)(11,14,18,22)(12,15,20,24)(17,21,19,23)(25,26,28,32)(27,34,35,30)(29,31,37,33)(36,39,40,38)(2,5)(3,7)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,27)(26,30)(28,35)(29,36)(31,38)(32,34)(33,39)(37,40) involution — undirected(9,12,13,20)(10,15,16,24)(11,17,18,19)(14,21,22,23)(26,31)(29,37)(30,38)(32,33)(34,39)(36,40)(1,3,4,7)(2,6,5,8)(11,18)(12,20)(14,22)(15,24)(26,32)(27,35)(31,33)(36,40)(2,5)(6,8)(11,18)(14,22)(17,19)(21,23) 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.