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