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