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