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