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