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