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