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