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