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