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