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