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