I usually make a seperate window to display only guildchat and call it "guild" haha.
If you hover over the chat with the mouse, at the top some tabs will appear. I believe there is a + symbol to add a new window/tabl. Right clicking a tab will also enable you to alter the settings and name of that tab.
This way, when you are looking for more people to do a group quest or something else in general or trade chat, you can select the "general" tab and you will see everything.. but if you are interested in only guildchat to have some fun, select the "guild" tab