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