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