First of all, I went through all the domino cards and found that a lot of them could be simplified. This would make it easier for me to to sort them out.
I then simplified the expressions on all the domino cards to their simplest forms (attatched in the solution from page-1 to page-3)
I then started to create the doughnuts by attatching the same terms, however, it was really puzzling to have a look at all these terms all together. To resolve this, I color coded the same terms with similar colors so that it becomes visually easy to sort.
Once this was done, it was super easy to create four doughnuts by attaching the same colour ends clockwise after trying a few combinations. Creating two large doughnuts was also not very difficult.
After creating two dounuts i went ahead to create a big doughnut using the same process I had used to make the previous two. Unlike the other two making the big doughnut took some time but after some trial and error I finally made it. There should be more possible ways of doing this because there are multiple dominoes with similar terms Ex: (a-b), (b-a), b occur 4 times, a occurs 3 times and other terms occur at least 2 times