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)(25,26,28,33,29,34,38,39)(27,32,37,40,36,30,35,31)(1,3)(2,6)(4,7)(5,8)(9,10,13,16)(11,17,18,14)(12,21,20,15)(19,22,24,23)(25,27)(26,30)(28,37)(29,36)(31,33)(32,34)(35,38)(39,40)(1,4,5,2)(3,7,8,6)(9,11)(10,14)(12,19)(13,18)(15,22)(16,17)(20,24)(21,23)(25,27,29,36)(26,31,34,40)(28,35,38,37)(30,39,32,33)(3,8)(6,7)(11,18)(14,17)(19,24)(22,23)(25,27)(26,32)(28,37)(29,36)(30,34)(31,39)(33,40)(35,38) involution — undirected(9,12,13,20)(10,15,16,21)(11,19,18,24)(14,22,17,23)(25,28,29,38)(26,33,34,39)(27,35,36,37)(30,40,32,31)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.