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