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)(27,32,30,40)(28,34,37,29)(35,36,38,39)(1,2)(3,8)(4,6)(5,7)(9,11,15,13)(10,16,14,18)(12,19,22,21)(17,23,20,24)(25,27,31,30)(26,32,33,40)(28,35,37,38)(29,39,34,36)(1,3,5,6)(2,4,7,8)(26,33)(28,37)(32,40)(35,38)(9,12)(10,17)(11,19)(13,21)(14,20)(15,22)(16,23)(18,24)(25,28)(26,34)(27,35)(29,33)(30,38)(31,37)(32,36)(39,40) involution — undirected(1,2)(3,4)(5,7)(6,8)(9,13,15,11)(10,16,14,18)(12,21,22,19)(17,23,20,24)(25,29,31,34)(26,28,33,37)(27,36,30,39)(32,38,40,35)(1,4)(2,6)(3,7)(5,8)(9,14,15,10)(11,18,13,16)(12,20,22,17)(19,24,21,23)(25,30,31,27)(26,32,33,40)(28,38,37,35)(29,39,34,36)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.