Clearest way to visualise temporal data?
How about using a boxplot, so you can also visualize the variance to some degree. Each boxplot could represent one weekday. 

When you look only at the mean (and be at the busstop at this time) you have a good chance to miss the bus (about 50% for a well-shaped non-skewed distribution).

You want to make sure that you be at the stop at the right time (95% chance of getting the bus or so). Therefore variance is important. 



The image is from this page: https://www.datamentor.io/r-programming/box-plot/

Alternatively, you could train a model on the arrival time, make predictions for each day, and plot the predicted value including a 95% confidence interval. But this probably is too much here.