You seem to have 2 problems:
1. You specify that your positions and normals are using a 16-bit float format, but your vertex struct contains 32-bit floats. You should use DXGI_FORMAT_R32G32B32A32_FLOAT, since that corresponds to the XMFLOAT4 type that you're using.
2. Your input layout has a "COLOR" element, but this element is not present in your VertexInfo struct.