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