Ah! You’re almost there. Try adjusting some properties on the noise node. First and foremost, you want to play with the scale — the look I achieved was based on using a scale of 0.05 or so. You could also try changing the function to Voronoi.
Check out this official UE4 blog post on using the updated noise node if you want to know more about the versatility and inner workings of the noise material node.