you can use yum groupinstall command to install these package at once. but for that you need a good internet connection. here is the complete command.
yum -y groupinstall "X Window System" "GNOME Desktop Environment" "KDE Desktop Environment"
if you have internet connection then it a magic :-) command and will install all dependencies at one and you dont need much struggle to run the Graphical Desktop Environment(KDE/GNOME).
