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