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