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