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