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