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