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