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