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