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