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