Email addresses in most cases will be automatically made clickable when the Participants Database “Make Links Clickable” setting is set. This is found under the “general” tab in the plugin settings.
As to matching the look of the submit button, I can’t help you with the details there, you just need to use your own CSS rules to get it to look the way you want. I suggest you use your Browser Developer Tools to inspect the HTML of a submit button that looks the way you want it to look, then create the CSS rules for the Participants Database submit button to match it.