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