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