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