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