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