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