The directory /home/kayon/public_html is usually made accessible by default by apache. It can be accessed as:
Files in this directory need to be world readable in order to be accessible through the server.
If it is not working then read on.
LoadModule userdir_module /usr/lib/apache/1.3/mod_userdir.so
That will allow Apache to look at a directory under the user's home directory named public_html.