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