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