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