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