It's a very easy task to do. Its as simple as dragging the field to Markscard Shelve(Color), and then adjusting the table calculation.
Step 1: For a simple running sum (for positioning the bars), you have to go and edit the table calculation, and select Compute using Advanced
Step 2: Drag all your fields to addressing.
Step 3: Sort your data by the master field (in your case the one that has Coffee, Coke,...) maximum (ascending or descending, doesn't matter)
This way it guarantee that the running sum is being applied to one category at a time (not one color at a time)
For more information you can go through the following link: http://onlinehelp.tableausoftware.com/current/pro/online/en-us/help.htm#calculations_tablecalculations_understanding_addressing.html