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