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)(13,17)(16,20)(18,21)(19,22)(23,24)(25,26,30,32)(27,34,37,38)(28,35,33,29)(31,39,40,36)(1,3,4,7)(2,5,6,8)(9,11)(10,14)(12,19)(13,18)(15,22)(16,23)(17,21)(20,24)(25,27,35,39,30,37,29,36)(26,31,28,38,32,40,33,34)(2,6)(5,8)(11,18)(14,21)(19,24)(22,23)(26,32)(28,33)(31,40)(34,38) involution — undirected(10,15)(12,20)(14,22)(16,17)(19,24)(21,23)(25,28,29,26,30,33,35,32)(27,34,36,40,37,38,39,31)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.