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