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)(11,19)(12,21)(13,17)(14,20)(15,18)(16,22)(23,24)(25,26,29,32)(27,30,34,37)(28,31,35,39)(33,38,40,36)(2,5)(6,7)(9,11)(10,12)(13,21)(14,16)(15,24)(17,19)(18,22)(20,23)(25,27)(26,30)(28,33)(29,34)(31,38)(32,37)(35,40)(36,39) involution — undirected(9,12,13,19)(10,16,17,24)(11,20,21,18)(14,23,15,22)(25,28)(26,31)(27,33)(29,35)(30,36)(32,39)(34,40)(37,38)(1,3,4,8)(2,6,5,7)(10,17)(12,19)(18,20)(22,23)(28,35)(31,39)(33,40)(36,38)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.