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)(11,17)(12,19)(13,16)(14,15)(18,24)(20,21)(22,23)(25,26)(27,32)(28,33)(29,31)(30,34)(35,38)(36,40)(37,39)(2,5)(6,7)(9,11,14,19)(10,12,15,17)(13,18,22,21)(16,20,23,24)(25,27,31,34)(26,32,29,30)(28,36,39,35)(33,40,37,38)(1,2)(3,6)(4,5)(7,8)(10,15)(12,17)(16,23)(20,24)(26,29)(27,34)(33,37)(35,36) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,11)(10,12)(13,21)(14,19)(15,17)(16,24)(18,22)(20,23)(25,28,31,39)(26,33,29,37)(27,35,34,36)(30,40,32,38)(1,3,4,8)(2,6,5,7)(9,12)(10,11)(13,20)(14,17)(15,19)(16,18)(21,23)(22,24)(25,29,31,26)(27,32,34,30)(28,37,39,33)(35,38,36,40)(9,13)(10,16)(11,18)(12,20)(14,22)(15,23)(17,24)(19,21)(25,30,31,32)(26,34,29,27)(28,38,39,40)(33,35,37,36)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.