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