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