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