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