Phoenix has a built-in bandwidth chart, so there’s no separate graphs login to deal with anymore.
For your account total, go to Billing > Bandwidth. The chart shows aggregate transit bandwidth across all of your servers, and you can switch the time range between 1h, 6h, 24h, 7d, and 30d (or expand it to fullscreen).
To see a single server’s bandwidth, open that server from Services > Servers and view the bandwidth chart on its detail page.