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