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