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