overfit random walk using ANN in Keras
Try changing your kernel regularizer. Either reduce its effect or shut it off entirely, then retrain and see what happens.

EDIT: I expect that the kernel regularizer is your best bet. You could also experiment with changing the depth of the network (number of layers) and how many units you give each layer. I would expect if you put more units into the layer that currently has 10, you'd see more overfitting.