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