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