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