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