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