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