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