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