The tour description makes no mention of visiting there. While it is also located in the Umbria region, the birthplace of St. Francis, the Basilica of San Francesco d'Assisi containing his crypt, and a Franciscan Monestary are located in the town of Assisi in the Provence of Perugia, located about 130 km (81 mi.) E./SE and about an hour and a half drive from Siena. You make a stop in Siena for a few hours on your way from Florence to Rome, so a side trip on your own to Assisi is likely impossible. To see where Assisi is located in relation to Florence and Rome go to Google maps or look at the route map for Tauck's Classic Italy.
There may be other, smaller. shrines to him throughout Italy, since St. Francis (along with Catherine of Siena) is the (co-) Patron Saint of Italy
If you really want to go, your best best is to extend your trip and travel from Rome. About 3 1/2 hours each way by train. There are two shrines to Francis in Assisi. The main basilica, as AlanS noted is on the Classic Italy tour. It holds Francis' tomb and some notable frescos by Giotto. The other sight worth seeing is the Basilica of Santa Maria degli Angeli (about 4km down the hill). It holds the small chapel from which the Franciscan order was established. That church is not on the tour (unless it has changed since we went in 2005). Our tour director tried to get us there, but traffic restrictions in that area prevented the bus from getting close enough. See the article on Assisi in Wikipedia for more information and pictures.
Comments
There may be other, smaller. shrines to him throughout Italy, since St. Francis (along with Catherine of Siena) is the (co-) Patron Saint of Italy
You'll just need to take a second trip to Italy!