Convert a tabular fleet activity report into a visual schedule by vehicle and sequential activity

Have a fleet of vehicles (>50) and get a tabular digital data set extract for total fleet by vehicle registration and vehicle size showing activity, start time and end time in 15 minute time interval buckets over a defined 1-4 day extract period. There are 7 defined activities and a colour code is assigned to each. Vehicle activity will rollover the 24 hour window. For visualisation purposes, want to convert this tabular data set into a visual colour coded activity schedule to identify dead activity times over the time period (single or multiple days) by vehicle registration and size of vehicle. In attached file is shown a sample of 2 vehicles over a 2 to 3 day period and a mock up of the visual schedule. By implication, any 15 minute time buckets that show blank have no activity. The visualisation time period will be from the start of the 1st active time period bucket to the end of the last active time period bucket in the tabular digital data set. For clarity, an activity starting at 10:00 and ending at 11:00 uses 4 time buckets, the 10:00, 10:15, 10:30 and 10:45 time bucket. It is then available for next activity starting at 11:00.