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