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