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