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