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