You can adjust most of the same format and size options for a list that you can for a container with one notable exception: you cannot change the size of a Visio list shape. Visio expands and contracts each list shape so it is the exact size of its member shapes plus the margin around the shapes.
The Format tool tab in the Container Tools tool tab set provides the functions described in the following list.
In the Size group:
You can use the Margins button to adjust the spacing between the edges of the list and the contained shapes.
Because Visio controls the size of a list shape, Fit To Container and Automatic Resize are disabled.
In the Container Styles group:
If you open a diagram created in Visio 2010 that contains a list, you can select one of 10 alternate styles for the list. However, at present, Visio 2013 does not allow you to change the style of lists created in Visio 2013.
The Heading Style gallery provides either two or four heading placement and style alternatives, depending on the list style.
In the Membership group: