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