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