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