Final answer:
The figure of speech in the given sentence is a metaphor. A metaphor is a comparison that doesn't use 'like' or 'as'. In this case, the dust storm is being compared to a living creature.
Step-by-step explanation:
The figure of speech in the given sentence is a metaphor.
A metaphor is a figure of speech in which a word or phrase is used to describe something by comparing it to something else, without using the words 'like' or 'as'. In this case, the dust storm is being compared to a living creature that swallows the small desert town and covers everything in a layer of dirt.