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