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