node { shape: point; }

[ A ] 
 -> [ B ] { point-style: square; }
 -> [ C ] { point-style: dot; }
 -> [ D ] { point-style: circle; }
 -> [ E ] { point-style: ring; }
 -> [ F ] { point-style: cross; }
 -> [ G ] { point-style: none; }
 -> [ H ] { point-style: star; }

