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