You need to install a kernel-devel package that matches your running kernel. From the output you presented, I see your running kernel is 2.6.32-279.el6. I strongly recommend you update it to... [by toracat]
Installation of the nvidia driver requires that you have a kernel-devel package that matches your running kernel. Your running kernel is a PAE type. When you do a 'yum install ... [by toracat]
I've just bought a new VPS with Cent OS 6.6 installed.