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