How do i get a silhouette head and shoulders contacts icon in Mail OS X El Capitan

Am finding El Capitan a pain when trying to send emails to a lot of people.

In Mavericks I used to have a little icon (silhouette head and shoulders) and I would simply be able to click on that and a list of my contacts would pop up and i could highlight each one that i wanted all in one go.

I can only see on El Capitan that you have to either start typing a persons name whereby it will autofill OR you must click the + sign at the top right and the list of contacts appears.

However using the + sign method is a pain because you have to click on name, then the email address of that person and then the box disappears so you have to click the + again. Which makes the process a laborious one!

Using the autofill method is all well and good but if you cannot think of every person you want to address email too it also is problematic particularly for people with poor memory!

Can anybody please tell me if it is possible to get that icon into the compose email field like it used to be?

Thanks