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