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