So you need to:
-Do a find for the last seven days of log entries
-Create an auto-enter date field with Creation Date, or date pulled from your timestamp field.
-Set the layout for your log table to be form view. Place a bar chart on the layout
-Under the data source area of your chart, select "Current Found Set" and "Summarized Data"
-Set the auto-enter date field as your X axis field and choose "date" format from x-axis options
-Set the count of traffic field as your Y axis and select "number" data type from y-axis options
-Sort the found set based on the auto-enter date field.
Is each log entry in a different record or do you have multiple log entries in a single field?
If the latter, I suggest changing your design to put each log entry in a different record.
each log entry is a separate record.