My ideas follow the same lines as post #3. The ideals of animalism are fairly clear, especially as defined by the seven commandments. You might make a stroyboard with a panel or two depicting each of the commandments.
Or, you might choose a couple of the commandments and create a brief set of panels that will tell a story related to those commandments.
You could start your storyboard with a drawing of the Manor Farm sign. The next few frames could show Farmer Jones neglecting the animals, the animals gathering to listen to Old Majors dream, the animals kicking in the feed shed and driving off the humans.
The next few frames after that could be: the sign changing from Manor Farm to Animal Farm, the pigs taking over, the humans trying to attack at the battle of cowshed but the animals winning, the animals dutifully working the farm, the pigs drinking and eating apples and trading with humans, the windmill going up and coming down, Boxer dying, the pigs looking like the humans, and then the sign morphing back from Animal Farm to Manor Farm.
That might be a nice overview of the plot visually.