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