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