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