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