People seem to be really confused by the show graph button. They do not recognize that the icon is a button. Perhaps add some text (despite possibly making it ugly) to make the purpose clear. Or some border.
I agree that making the fact that the icon acts as a button more apparent would be good. Additionally, it might help to pull in this icon from Material Design Icons (a community icon.)
People seem to be really confused by the show graph button. They do not recognize that the icon is a button. Perhaps add some text (despite possibly making it ugly) to make the purpose clear. Or some border.