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