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