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