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