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