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)(11,19,20,37)(12,23,27,39)(13,28,25,17)(15,30,31,21)(16,33,35,26)(22,38,29,34)(24,36,40,32)(1,2)(3,6)(4,8)(5,7)(9,11)(10,15)(12,24)(13,29)(14,20)(16,34)(17,36)(18,31)(19,23)(21,26)(22,25)(27,40)(28,32)(30,33)(35,38)(37,39) involution — undirected(1,2)(3,6)(4,8)(5,7) involution — undirected(1,3,5,4)(2,6,7,8)(11,20)(15,31)(19,37)(21,30)(22,29)(24,40)(32,36)(34,38)A 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.