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