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