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