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