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