If you are only using us with PayPal Payments Standard, buyers will only see a PayPal checkout button in their shopping cart; however, the PayPal Standard checkout site can usually offer a card-based payment option for buyers who don't have a PayPal account.
First make sure you have taken the free upgrade to a PayPal Business or Premier account that is PayPal Verified, and in your PayPal account under [your name] > Account Settings > Website Payments > Website Preferences, make sure you have set PayPal Account Optional: ON.
Once you have that set up, when a buyer clicks the PayPal checkout button in your cart, PayPal's checkout site should offer the choice to log into PayPal or Pay With a Credit or Debit Card.
Note that buyers cannot pay with a card that is already linked to a PayPal account. The PayPal checkout site also will not offer the card payment option if you are using us with PayPal Payments Pro, or if the buyer is located in a country where PayPal doesn't support card payment without a PayPal account.
If you want your cart to show a separate checkout button for card payments, you will need to add one of the other payment services we support listed here. In this case, buyers who wish to pay with a card would simply click the dedicated Pay With Card checkout button in your cart, rather than clicking the PayPal checkout button.