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