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