Mr Shorten told the audience at Perth's ritzy Crown Towers complex that Australia should also be using the experience of other former leaders.
"Turnbull, love him or hate him, he's got skills. Same goes for Julia, same goes for Kevin ... Even John Howard's got something to do for the nation, too," he said.
"We've got to be better about our former politicians than pushing them on the scrap heap."
Mr Shorten also promised to hold a summit of business, employers and unions to discuss wages and the economy within weeks of coming to office if Labor wins government on Saturday.
"I want to get business, unions, small business in the same room at the same time," he said, adding it would not be like the formal wages "accord" that former prime minister Bob Hawke made with the Australian Council of Trade Unions in the 1980s.
In a bid for the business community's support, Mr Shorten also told the breakfast he would bring his cabinet to Perth and seek to amend the Fair Work Act to extend "greenfields agreements" for mega projects such as mining ventures with the aim of providing certainty over pay and conditions for multibillion-dollar projects with a lifespan of more than three years.
"Whatever your politics may be, if you think that's a good idea you should vote for me on Saturday," he said.
"I want to ask you as leaders to exercise your judgment ... is our nation currently heading in the right direction?"
Five seats are considered in play in Western Australia, including four held by the Liberal Party.
Later on Wednesday, Mr Shorten campaigned at a TAFE in the electorate of Pearce in outer Perth later. He will then travel to Sydney, where he will give his last major address of the campaign on Thursday.
Pearce is held by Attorney-General Christian Porter on a margin of 3.6 per cent. Labor is running former police officer Kim Travers and has high hopes of taking the seat.