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