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