I have actually followed this example and it worked for me 🙂
NameVirtualHost *:80
<VirtualHost *:80>
ServerName mysite.example.com
Redirect permanent / https://mysite.example.com/
</VirtualHost>
<VirtualHost _default_:443>
ServerName mysite.example.com
DocumentRoot /usr/local/apache2/htdocs
SSLEngine On
# etc...
</VirtualHost>
Then do:
/etc/init.d/httpd restart