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