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