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