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