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