The image you’ve posted is from a Krizhevsky et al. 103 and shows the learned filter kernels.
You are not seeing a feature map, but 96 kernels of size 3x11x11.
To get a similar image, you can use this code snippet:
from torchvision.utils import make_grid

kernels = model.extractor[0].weight.detach().clone()
kernels = kernels - kernels.min()
kernels = kernels / kernels.max()
img = make_grid(kernels)
plt.imshow(img.permute(1, 2, 0))