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