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