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