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