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