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