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