You will need to use the Health and Utilization add-on to LMS to do this. HUM is available as a 90-day eval starting in LMS 3.0.1. HUM provides functions similar to those of MRTG, cricket, cacti, etc.

Using HUM, you would need to set up a poller under HUM > Poller > Poller Management > Create. Specify the Interface Utilization template, and select the devices (and instances) you want to monitor.