Personal PayPal accounts cannot offer buyers the option to pay with a card if they don't have a PayPal account; to offer the card payment option, you must have at least a PayPal Business or Premier account, and also set PayPal Account Optional: ON in your in your PayPal account under Profile > Profile & Settings > My Selling Tools > Website Preferences.
We recommend getting the free upgrade to a PayPal Business account anyway, which should also lift your monthly payment receiving limit and allow you to specify a business name that would be shown during checkout and in PayPal payment references (rather than showing buyers your PayPal Email address), among other business-minded amenities. You can use this link to upgrade to Business if you haven't already:
http://short.e-junkie.com/paypal-business