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