For a book about architectural layout and design, the cover design should reflect the essence and aesthetics of architecture. It could feature an eye-catching image of a striking architectural structure or blueprint, conveying the theme of the book at a glance. Utilizing clean lines, geometric shapes, and bold typography can evoke the precision and creativity inherent in architectural design. Incorporating elements such as blueprints, sketches, or iconic architectural landmarks can further enhance the visual appeal and convey the book's content effectively.