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