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