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