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