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