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