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