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