No (if you mean buttons which always show their borders even when not "pushed in" and when the mouse isn't over them).
The main button appearance settings are in Settings -> Preferences / Display / Toolbars.
Per-toolbar settings are in Settins -> Customize / Toolbars
Per-button settings are in the buttons themselves.
You can change the way buttons look quite a lot but there's no "always show borders" option or similar.
If the problem is visually separating the drive buttons, the Go DRIVEBUTTONS command has options which may help. It can show any combination of icons, letters and labels. As with other buttons you can choose whether the labels should appear next to or below the icons.
My preference is to use these icons so that the letters/labels aren't needed at all: