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