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