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