You can create the file /etc/cron.daily/slocate with the following permissions:
-rwxr-xr-x 1 root root 50 2006-04-19 14:56 /etc/cron.daily/slocate
and with the following content:
/usr/bin/updatedb -c /etc/updatedb.conf
You may need to modify the location of updatedb for your system. I'm also assuming that you have /etc/updatedb.conf on your system and that it points to /var/lib/slocate/slocate.db...