I hope you haven't spent too long on this, because it's impossible.

Colour the row shown as 1,2,3,4. Now cell a can be either 1 or 4 - it doesn't matter which as the figure is symmetric - so we'll say 1. Cell b must therefore be 2, cell c must be 4, and cell d must be 2.

We now can't colour in cell e, so the puzzle can't be done.

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