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