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