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