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