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)(11,23)(12,17)(13,28)(14,20)(15,21)(16,22)(18,26)(19,29)(24,38)(25,33)(27,37)(30,35)(31,36)(32,39)(34,40) involution — undirected(2,5)(6,8)(9,11,14,12,16,26,15,25)(10,17,21,23,22,33,20,18)(13,24,29,27,30,39,31,40)(19,32,28,37,36,38,35,34)(1,3,4,7)(2,6,5,8)(9,12,14,26,16,25,15,11)(10,18,21,17,22,23,20,33)(13,27,29,39,30,40,31,24)(19,34,28,32,36,37,35,38)(9,13)(10,19)(11,24)(12,27)(14,29)(15,31)(16,30)(17,32)(18,34)(20,35)(21,28)(22,36)(23,37)(25,40)(26,39)(33,38) involution — undirected(9,14,16,15)(10,20,22,21)(11,12,26,25)(13,29,30,31)(17,18,33,23)(19,35,36,28)(24,27,39,40)(32,34,38,37)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.