You will have to configure an Active Directory Synch task (it's under Server tasks) to do that. Take a look at the following KB https://kc.mcafee.com/corporate/index?page=content&id=KB51402 and/or on the product guide.
Note1: Another way that you have in ePO to find PCs and deploy automatically McAfee Agents is the Rogue System Detection, more info are available on the product guide for ePO - https://kc.mcafee.com/resources/sites/MCAFEE/content/live/PRODUCT_DOCUMENTATION/ 20000/PD20053/en_US/epo_402_product_guide_en-us.pdf .
Note2: Be aware that latest version of ePO is 4.5 Patch 3.
Hope this helps.