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