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