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