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