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