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