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