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