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