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