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