In your themes style.css find this:
/************************************************
* Content *
************************************************/
Any where under there, Put this code:
#wpcf label {
clear: both;
display: block;
float: left;
width: 150px;
}
#wpcf input {
float: left;
width: 200px;
padding: 1px;
margin: 2px 5px 2px 0;
}
#wpcf textarea {
width: 350px;
height: 100px;
padding: 1px;
margin: 0 5px 10px 0;
}
#wpcf #contactsubmit {
margin-left: 250px;
width: 100px;
}
The code is found on plugin site at https://yoast.com/wordpress/enhanced-wordpress-contact-form/
Hope this helps.