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