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