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