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