yum grouplist

yum groups install “GNOME Desktop”
or
yum groupinstall “GNOME Desktop”

yum groups install “Server with GUI”
or
yum groupinstall “Server with GUI”

systemctl set-default graphical.target

systemctl start graphical.target

 How to change the reunlevel in rhel-7 or centos-7

systemctl list-units –type=target

systemctl get-default

systemctl set-default multi-user.target

systemctl get-default

reboot