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