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