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