Apmex has that where you can overlay graphs. Just click on the gold or silver spot price tab, the chart will pop up and then click on usd, sp500 or whatever it shows. There are a few options.
You can do it with Tradingview but you'll need to create a free account. You can bring up a chart of the US dollar currency index by opening Tradingview and search for its ticker "DXY" and a chart will open up. Then in the top left corner next to the green $ for the DXY click on "+" and add the S&P 500 ticker "SPX", do the same for the price of gold in USD by adding the ticker "XAUUSD" and you get get the chart below. If you want to add silver use the ticker XAGUSD, XPTUSD for platinum, XPDUSD for palladium. You can chuck in the tickers for companies, ETFs etc but there's no ticker for the price of cocaine in USD. Edit to add: you can save that chart online to revisit at a later stage, or save it to file and flash it out to friends at parties or golf.
Alterantively, print off a copy of the DXY, hold a mirror along the "X" axis and there's your gold chart.