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