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)(11,16,12,17)(13,18,22,21)(19,23,20,24)(25,26)(27,28)(29,33)(30,31)(32,35)(34,36)(37,39)(38,40)(1,2)(3,5)(4,6)(7,8)(9,11,15,12)(10,16,14,17)(13,19,22,20)(18,23,21,24)(25,26,30,31)(27,28,32,35)(29,33,37,39)(34,36,38,40)(1,3,4,7)(2,5,6,8)(10,14)(16,17)(18,21)(23,24)(26,31)(28,35)(29,37)(34,38)(9,12,15,11)(10,17,14,16)(13,19,22,20)(18,23,21,24)(25,27,30,32)(26,28,31,35)(29,38,37,34)(33,40,39,36)(9,13)(10,18)(11,19)(12,20)(14,21)(15,22)(16,23)(17,24)(25,28)(26,32)(27,31)(29,36)(30,35)(33,38)(34,39)(37,40) involution — undirected(9,14,15,10)(11,17,12,16)(13,21,22,18)(19,24,20,23)(25,29,30,37)(26,33,31,39)(27,34,32,38)(28,36,35,40)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.