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