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