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