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