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