The simplest visualisation would be a Confirmed Cases vs Time graph. But anyone with a basic math background would figure out this graph is of little to no help as it hardly takes into account the demographic of a country, point of outbreak etc.
The plot below gives a representation of Active Cases vs Days since 100 confirmed graph would look like.
Active Cases in pretty much every country except for China is still on the rise but China has done brilliantly over a period of a month or two in eliminating the number of active cases.
To better compare how each country has dealt with the virus, we plot the second graph.
For the second graph, we calculate the percentage increase in confirmed cases since the previous day country-wise.
The percentage increase gives us a better insight at how efficient the countries have been in containing the infection. It is calculated as (Confirmed Cases Today - Confirmed Cases Yesterday)*100/Confirmed Cases Yesterday
Now this graph gives a very different picture on China and other countries likewise. While Mainland China has much more cases of infection, the percentage increase in infected people is very less compared to other countries like US, India etc.