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