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