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