Point cloud has attracted more and more attention in 3D object representation, especially in free-view rendering. However, it is challenging to efficiently deploy the point cloud due to its huge data amount with multiple attributes including coordinates, normal and color. In order to represent point clouds more compactly, we propose a novel point cloud compression method for attributes, based on geometric clustering and Normal Weighted Graph Fourier Transform (NWGFT). Firstly, we divide the entire point cloud into different sub-clouds via K-means based on the geometry to acquire sub-clouds with more uniform structures, which enables efficient representation with less cost. Secondly, for the purpose of reducing the redundancy further, we apply NWGFT to each sub-cloud, in which graph edge weights are derived from the similarity in normal. Finally, extensive experimental results show that, compared with traditional transform based point cloud compression, the proposed approach achieves about 34.34% bit rate reduction on average for Y components of color.