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