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