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