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