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