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