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