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