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