Final answer:
The figurative language suggests a sense of purpose and ambition in Gatsby's pursuit of wealth.
Step-by-step explanation:
The figurative language in this passage has the effect of suggesting a steady and insistent calling that Gatsby later pursues by becoming wealthy. The image of the "drums of his destiny" portrays a sense of purpose and ambition that drives Gatsby towards his future glory. This figurative language helps establish a sense of determination and anticipation in the plot of the novel.