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