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